This invention relates generally to computer systems, and more particularly to graphical user interfaces for computer systems.
Graphical user interfaces or GUI are becoming increasingly popular with computer users. It is generally accepted that computers having graphical user interfaces are easier to use, and that it is quicker to learn an application program in a GUI environment than in a non-GUI environment.
A relatively new type of computer which is well suited for graphical user environments is the pen-based computer system. A pen-based computer system is typically a small, hand-held computer where the primary method for inputting data includes a "pen" or stylus. A pen-based computer system is often housed in a relatively flat enclosure, and has a dual-function display assembly which serves as both an input device and an output device. When operating as an input device, the display assembly senses the position of the tip of a stylus on the viewing screen and provides this positional information to the computer's central processing unit (CPU). Some display assemblies can also sense the pressure of the stylus on the screen to provide further information to the CPU. When operating as an output device, the display assembly presents computer-generated images on the screen.
The dual-function display assemblies of pen-based computer systems permit users to operate the computer as a computerized notepad. For example, graphical images can be input into the pen-based computer by merely moving the stylus across the surface of the screen. As the CPU senses the position and movement of the stylus, it generates a corresponding image on the screen to create the illusion that the stylus is drawing the image directly upon the screen, i.e. that the stylus is "inking" an image on the screen. With suitable recognition software, text and numeric information can also be entered into the pen-based computer system in a similar fashion. Besides serving as a notepad, pen-based computers can provide a number of useful functions, such as serving as an address book, an appointment calendar, a to-do list, etc.
Most personal computer systems (including pen-based computer systems) include a real-time clock which provides time and date information. Real-time clocks are useful for date and time stamping documents and folders, and for providing current date and time information to application programs such as the aforementioned appointment calendar and to-do list. Real-time clocks are typically battery powered independently of the remainder of the computer system circuitry so that they don't have to be reset every time the computer system cycled off and then on.
Real-time clocks do, nevertheless, have to be reset from time to time. For example, if the battery powering the real-time clock dies, the real-time clock will have to be reset after the battery is replaced. The real-time clock also is frequently reset at the switch-over between Daylight Savings Time and Standard Time, and when the computer system is moved to a new time zone.
In the prior art, real-time clocks are often reset by typing in a new time or date from a keyboard. An example of an entry screen for resetting a real-time clock is as follows:
Current time: 08:14:30 PA1 New time: (HH:MM:SS): :: PA1 Time: 08:14:30
The new hour, minutes and seconds are typed in, and the system real-time clock is reset.
Alternatively, some pointer based computer systems provide up and down arrows which permit a digital display of a real-time clock to be reset. An example is as follows:
The clock is reset by first selecting either the hour, minutes, or seconds from the digital display with the pointer and then selecting either the up arrow or the down arrow with the pointer to scroll the selected hour, minutes or seconds up or down, respectively.
The first of these two methods for resetting a real-time clock is not particularly attractive for pen-based computer systems, since it is more suited for keyboard entry than stylus entry. The second of the two methods is suitable for pen-based computer systems, but does not take advantage of the rich graphical potential of pen-based computer systems.